Cyclin D1和p16、p27在脑胶质瘤中的表达及其与PCNA的相关性

目的 :检测CyclinD1 和p16、p2 7以及PCNA在脑胶质瘤中的表达状况 ,以探讨不同病理类型脑胶质瘤中各自的表达及其相关性。方法 :应用免疫组化S P法 ,检测 12例正常脑组织、5 8例脑胶质瘤组织中CyclinD1 、p16、p2 7及PCNA表达及其特征。结果 :CyclinD1 在由低度恶性胶质瘤向高度恶性胶质瘤转化中阳性表达逐渐增强 (χ2 检验 ,P <0 0 0 5 ,χ2 =5 1 6 7) ;而p16、p2 7阳性表达却是随着胶质瘤恶性程度的升高而降低 (χ2 检验 ,P值均 <0 0 0 5 ,χ2 分别为 15 4 1和 12 81)。CyclinD1 与PCNA呈正相关 ,rs =0 74 5 ;p16和p2 7与PCNA呈负相关 ,rs分别为 - 0 5 6 6和 - 0 6 12。结论 :脑胶质瘤中CyclinD1的表达程度对胶质瘤的细胞增殖活性起促进作用 ,而p16、p2 7的表达则起抑制作用。     

胃肠道类癌中p27^kipl、PCNA表达及p16基因缺失

目的：探讨p27^kipl、PCNA及p16与胃肠道类癌转移的关系。方法：采用免疫组化SABC法检测25例胃肠道类癌组织中p27^kipl和PCNA蛋白表达，同时用PCR法检测p16基因的缺失情况。结果：p27^kipl在胃肠道癌阳性表达率为64％（16／25），PCNA I－Ⅱ级和Ⅲ-Ⅳ级表达率分别为56％、44％。2种蛋白阳性表达率与分化程度无相关性（P＞0．05），与淋巴结转移相关（P＜0．05）。p27^kipl与PCNA表达负相关。p16基因纯合性缺失率为48％（12／25），其缺失率与类癌分化程度和淋巴结转移无关。结论：p27^kipl低表达、PCNA高表达与胃肠道类癌转移有关，胃肠道；类癌的发生与p16基因缺失有关，但可能为早期分子事件。     

p16 mRNA及其蛋白、EGFR在脑胶质瘤中的表达

目的：通过观察脑胶质瘤中ｐ１６ ｍＲＮＡ及其蛋白、ＥＧＦＲ的表达,探讨其在脑胶质瘤发生、发展中的作用。方法：应用原位杂交技术和免疫组织化学方法在３８例人脑胶质瘤中检测ｐ１６ ｍＲＮＡ及其蛋白、ＥＧＦＲ的表达。以７例正常组织为对照。结果：ｐ１６ｍＲＮＡ和ｐ１６蛋白在Ⅲ～Ⅳ级、Ⅰ～Ⅱ级胶质瘤、正常组织中的阳性表达率分别为８．３％,１６．７％;５３．７％,５７．７％;７１．４％,８５．７％。ＥＧＦＲ在Ⅲ     

上皮性卵巢癌中Cyclin D1和p27的表达及其临床意义

目的探讨Cyclin D1和p27蛋白在上皮性卵巢癌中的表达及其与临床病理间的关系。方法利用免疫组化S-P法测定Cyclin D1和p27蛋白在62例上皮性卵巢癌中的表达,比较Cyclin D1、p27蛋白与卵巢癌的各项临床病理指标间的关系及两者间的关系。结果在上皮性卵巢癌中,Cyclin D1蛋白的表达在FIGO分期Ⅰ-Ⅱ期低于Ⅲ-Ⅳ期,组织学G1-G2组低于G3组,术后残留癌组织≤2cm组低于〉2cm组,淋巴无转移组低于有转移组;而p27蛋白在FIGO分期Ⅰ-Ⅱ期高于Ⅲ-Ⅳ期,组织学G1-G2组高于G3组,淋巴无转移组高于有转移组,以上各组间均有统计学差异（P〈0.05）;在上皮性卵巢癌中Cyclin Dl、p27蛋白的表达呈负相关（rs=-0.255,P〈0.05）。结论CyclinDl、p27蛋白的异常表达可能与上皮性卵巢癌的发展及恶性程度有关,可作为评估上皮性卵巢癌恶性程度和预后的指标。     

p27kip1、p16蛋白和增殖细胞核抗原在鼻咽癌中的表达及其意义

目的 研究p27^kip1、p16蛋白及增殖细胞核抗原(PCNA)在鼻咽癌(NPC)组织中的表达,探讨它们之间的关系及其与．NPC生物学行为及预后的相关性。方法应用免疫组织化学EnVision两步法检测66例鼻咽非角化性癌(NKC)组织和25例鼻咽黏膜慢性炎症(NP)组织中p27^kip1、p16蛋白及PCNA表达水平。结果(1)．NKC组织中p27^kip1、p16阳性表达率分别为65％、68％;与NP组比较,差异有统计学意义(P＜0．05)。(2)＜、p16蛋白在NKC中的表达与NKC颅神经侵犯及治疗后5年生存率有关(P＜0．05),与临床分期、淋巴结转移无关(P＞0．05);PCNA表达与．NKC临床分期及治疗后5年生存率有关(P＜0．05),与淋巴结转移、颅神经侵犯无关(P＞0．05)。(3)p27^kip1、p16及PCNA阳性表达之间有相关性(P＜0．05)。结论检测p27^kip1、p16蛋白及PCNA有助于综合评估NKC的预后。     

Cyclin D2和p16蛋白表达在心肌细胞增殖、分化中的变化

目的:探讨cyclinD₂、p16蛋白表达与新生大鼠心肌细胞体外培养早期增殖、分化的关系及意义。方法:培养出生后1d大鼠心肌细胞,予生长曲线、流式细胞计数检测培养过程中增殖改变,透射电镜观察超微结构变化,免疫细胞化学结合图像分析检测心肌细胞内cyclinD₂、p16蛋白变化。结果:①生长曲线、流式细胞计数显示:心肌细胞在培养的前3d内具有一定增殖能力,但呈下降趋势同时逐步分化;3d后增殖能力丧失。超微结构显示细胞内有大量肌丝和线粒体。②心肌细胞在培养的5d中,cyclinD₂表达量在第3、4、5d分别是第1d的89.99%(P＜0.05)、83.61%(P＜0.05)和69.65%(P＜0.01);p16表达量在2、3、4、5d分别是第1d的1.63倍、1.72倍、1.99倍和2.84倍(均P＜0.01)。结论:新生大鼠心肌细胞出生后早期体外培养前3d有一定增殖能力,但呈下降趋势同时逐步分化;cyclinD₂表达下调和p16表达上升可能参与心肌细胞早期分化。     

p16与p27蛋白在宫颈癌中的表达及意义

宫颈癌是威胁妇女生命健康的主要恶性肿瘤，目前低年龄组宫颈癌的患病率有上升趋势，因此对宫颈癌发病机制的研究倍受关注。宫颈癌中很少见到p53基因改变，检测p16、p27蛋白在宫颈癌及其周围正常宫颈组织的表达，有利于探讨它们与宫颈癌发生、发展的关系。     

Cyclin D1和p16蛋白在胎儿心肌细胞中的表达

心肌细胞从胚胎期具有增殖能力的细胞成为成年期不具有增殖能力而只有发生肥大反应能力的过程中,存在增殖能力的变化和逐渐分化现象,该现象受细胞周期调控。细胞周期素(cyclin)是对细胞周期起正性调节作用的一类物质。p16蛋白是细胞周期素依赖的蛋白激酶     

胃肠道类癌中p27kip1、PCNA表达及p16基因缺失

目的 :探讨 p2 7kip1 、PCNA及 p1 6与胃肠道类癌转移的关系。 方法 :采用免疫组化SABC法检测 2 5例胃肠道类癌组织中p2 7kip1 和PCNA蛋白表达 ,同时用PCR法检测 p1 6基因的缺失情况。 结果 :p2 7kip1 在胃肠道类癌阳性表达率为 64 % (1 6/ 2 5) ,PCNAⅠ～Ⅱ级和Ⅲ～Ⅳ级表达率分别为 56 %、44 %。 2种蛋白阳性表达率与分化程度无相关性 (P >0 0 5) ,与淋巴结转移相关 (P <0 0 5)。p2 7kip1 与PCNA表达负相关。p1 6基因纯合性缺失率为 48% (1 2 / 2 5) ,其缺失率与类癌分化程度和淋巴结转移无关。结论 :p2 7kip1 低表达、PCNA高表达与胃肠道类癌转移有关 ,胃肠道 ;类癌的发生与p1 6基因缺失有关 ,但可能为早期分子事件。     

p16和cyclin D1在甲状腺癌中的表达

我们采用Ｓ－Ｐ免疫组化法，检测ｐ１６基因和ｃｙｃｌｉｎＤ１基因在甲状腺癌中的表达，并比较两者之间可能存在的联系。１材料和方法１．１标本收集我院１９８０～１９９５年甲状腺癌手术切除标本５３例，其中乳头状癌２８例，滤泡癌１１例，髓样癌１４例。标本均经常规...     

Distribution of D1 and D5 dopamine receptors in the primate nucleus accumbens

The D1 family of dopamine receptors (D1R) play a critical role in modulating reward in the nucleus accumbens (NAc). A better understanding of how D1Rs modulate NAc function must take into account the contributions of the two D1R subtypes, D₁ and D₅. In order to determine how these two subtypes contribute to dopamine's actions in the NAc, we utilized subtype specific antibodies and immunoelectron microscopy to quantitatively determine the localization of D₁ and D₅ in the neuropil of the primate NAc. We found that D₁ was more commonly found in dendritic shafts and spines, while D₅ was more commonly found in axon terminals, preterminal axons and glial processes. However, D₅ is well positioned to play an important role in postsynaptic modulation of inputs onto NAc medium spiny neurons. Approximately one third of spines contained D₁ and one quarter contained D₅, and as we have previously observed in the prefrontal cortex (PFC) and amygdala, these receptors overlapped extensively in dendritic spines. Similarly, we found overlap of the two D1R in axon terminals in the NAc; however, here D₅ labeled the larger population of terminals and D₁ was found in a subpopulation of D₅ containing terminals. Given the higher affinity of D₅ for dopamine, this suggest that presynaptic modulation of inputs by dopamine may be more easily evoked than in PFC where D₁ is the dominate presynaptic receptor. Finally, we investigated differences between the NAc and the dorsal striatum. We found that in the caudate half of dendritic spines contain D₁, significantly more than in the NAc. This suggests differences in how receptor is translated and distributed in D₁ mRNA expressing medium spiny neurons in the NAc and caudate.     

Decline in striatal dopamine D1 and D2 receptor activation in aged F344 rats

Aging differentially affects receptor function. In the present electrophysiological study we compared neuronal responsiveness to locally applied dopamine D₁ and D₂ receptor agonist in the striatum of female Fischer 344 rats aged 3 and 26–27 months. In a subgroup of the old rats, the nigrostriatal dopamine bundle was destroyed unilaterally with 6-hydroxydopamine (6-OHDA) to assess receptor plasticity in response to denervation. Spontaneous firing rate of striatal neurons was higher in aged compared to young rats. Higher doses of the D₁ agonist SKF 38393 or the D₂ agonist quinpirole were required to elicit a 50% change in firing rate in aged compared to young rats. No difference with SKF 38393 or quinpirole was detected between 6-OHDA denervated and control (nonlesioned) striatum in aged rats. Supersensitivity to D₂ agonists has been reported following 6-OHDA lesions in young rats. These observations suggest that D₂ receptors in aged rat striatum might not be as plastic as in younger rats.     

Functional differences between D1 and D5 revealed by high resolution imaging on live neurons

The interaction between the dopaminergic and glutamatergic systems governs normal behavior and is perturbed in many psychiatric disorders including schizophrenia. Hypofunction of the D1 family of receptors, to which the D₁ and D₅ subtypes belong, is a typical feature of schizophrenia. Here we have used confocal live cell imaging of neurons to examine the distinct roles of the D₁ and D₅ receptors in the intra-neuronal interaction with the glutamatergic system. Using fluorescently tagged D₁ or D₅ expressed in cultured striatal neurons, we show that both receptor subtypes are primarily transported via lateral diffusion in the dendritic tree. D₁ is to a much larger extent than D₅ expressed in spines. D₁ is primarily expressed in the head whereas D₅ is largely localized to the neck of the spine. Activation of N-methyl-d-aspartic acid (NMDA) receptors slowed the diffusion rate and increased the number of D₁ positive spines, while no effect on D₅ diffusion or spine localization could be observed. The observed differences between D₁ and D₅ can be attributed to structural differences in the C-terminus and its capacity to interact with NMDA receptors and PSD-95. Identification of a unique role of D₁ for the intra-neuronal interaction between the dopaminergic and glutamatergic systems will have implications for the development of more specific treatments in many neuropsychiatric disorders.     

中、重度负重游泳运动训练对肾上腺Cyclin D1表达的影响

目的研究长期游泳训练后大鼠肾上腺Cyclin D1的表达变化。方法成年SD大鼠分为中度负重(占体重3%)和重度负重(占体重5%)游泳训练2组。大鼠在水槽内进行6周训练,每天1h。6周时,取肾上腺用RT-PCR检测Cyclin D1表达水平,用t检验进行统计分析。结果重度负重导致肾上腺Cyclin D1表达上调,与中度负重组比,差异有统计学意义(P<0.05)。结论重度游泳训练明显上调肾上腺Cyclin D1水平,提示Cyclin D1在游泳训练的肾上腺发挥有作用。     

Chronic passive exposure to aggression decreases D2 and 5-HT1B receptor densities

It has been recently reported that passive exposure to aggression induces aggressive behavior in a rodent model. However, it remains unclear whether this response is correlated with neurochemical changes that correspond either to stress-induced aggression or non-stressed, learned aggression. Stress-induced aggression has been shown to result in increased brain dopamine D₂ receptor and serum corticosterone levels. In contrast, learned aggression is probably associated with reward deficiency syndrome, characterized by low dopamine D₂ receptor levels, without stress effects (i.e., high corticosterone levels). We hypothesized that chronic passive exposure to aggression would produce learned aggression, represented by low levels of dopamine D₂ receptor binding but normal levels of stress hormone. The present study additionally focused on serum testosterone and serotonin 5-HT_1B receptor density that has been associated with aggression/reward circuits. Hormonal results indicated that there were no differences between the “observer” rats that had been passively exposed to aggression and non-aggression for 10 min/day for 23 consecutive days. However, receptor binding autoradiography identified lower densities of dopamine D₂ receptors in the cortical-accumbal regions (shell of the nucleus accumbens and cingulate and motor cortices) and lower 5-HT_1B receptor densities in the tegmental regions (ventral tegmental area, substantia nigra pars compacta, and periaqueductal gray) among observers exposed to aggression, compared to controls. Changes in dopamine D₂ receptor densities due to chronic exposure to aggression do not resemble those patterns reported for stress-induced aggressive behavior. Our evidence suggests that the development of aggressive behavior among passive observers occurs through a learned, and not a stress-induced, mechanism.     

Bifeprunox and aripiprazole suppress in vivo VTA dopaminergic neuronal activity via D2 and not D3 dopamine autoreceptor activation

Bifeprunox and aripiprazole are two novel antipsychotics presenting partial agonistic activity for the D₂ and D₃ dopamine (DA) receptors. Using in vivo electrophysiological paradigms in anaesthetized rats, we have previously shown that both drugs independently inhibit the spontaneous firing and bursting activity of ventral tegmental area (VTA) dopaminergic neurons and partially reverse the suppressing effect of the full DA receptor agonist apomorphine. Moreover, we have also shown that the D_2/3 receptor antagonist haloperidol prevents the inhibitory effects of these antipsychotics, confirming their partial D₂-like agonistic activities [L. Dahan, H. Husum, O. Mnie-Filali, J. Arnt, P. Hertel, N. Haddjeri, Effects of bifeprunox and aripiprazole on rat serotonin and dopamine neuronal activity and anxiolytic behaviour, J. Psychopharmacol. (2009)]. In the present electrophysiological study, selective antagonists of D₂ and D₃ receptors were used to further characterize the inhibitory role of bifeprunox and aripiprazole on the D₂ and D₃ receptors in vivo. Administration of bifeprunox (250 μg/kg, i.v.) or aripiprazole (300 μg/kg, i.v.) reduced the firing activity of VTA DA neurons by 40–50%. The bursting activity was reduced by 95% and 77% by bifeprunox and aripiprazole, respectively. Systemic administration of the preferential D₃ receptor antagonist GR218,231 (200 μg/kg, i.v.) did not modify the inhibitory effect of bifeprunox or aripiprazole, either on the firing or on the bursting activity. On the other hand, the preferential D₂ receptor antagonist L741,626 (500 μg/kg, i.v.) completely blocked the inhibitory effect of both bifeprunox and aripiprazole on the VTA DA neuronal activity. The present study shows that bifeprunox and aripiprazole behave as partial D₂, but not D₃, receptor agonists in vivo, inhibiting the firing activity (preferentially the phasic activity) of VTA DA cells.     

Dopamine D1 receptors and age differences in brain activation during working memory

In an fMRI study, 20 younger and 20 healthy older adults were scanned while performing a spatial working-memory task under two levels of load. On a separate occasion, the same subjects underwent PET measurements using the radioligand [¹¹C] SCH23390 to determine dopamine D₁ receptor binding potential (BP) in caudate nucleus and dorsolateral prefrontal cortex (DLPFC). The fMRI study revealed a significant load modulation of brain activity (higher load > lower load) in frontal and parietal regions for younger, but not older, adults. The PET measurements showed marked age-related reductions of D₁ BP in caudate and DLPFC. Statistical control of caudate and DLPFC D₁ binding eliminated the age-related reduction in load-dependent BOLD signal in left frontal cortex, and attenuated greatly the reduction in right frontal and left parietal cortex. These findings suggest that age-related alterations in dopaminergic neurotransmission may contribute to underrecruitment of task-relevant brain regions during working-memory performance in old age.     

Modulation of AMPA currents by D1-like but not D2-like receptors in spinal motoneurons

Dopamine can modulate and excite spinal locomotor networks, affect afferent transmission and increase motoneuronal excitability. One of the mechanisms whereby dopamine increases motoneuronal excitability is to potentiate AMPA channel-mediated glutamatergic transmission onto motoneurons. However, it is not known which dopaminergic receptor subtypes or the intracellular mechanisms contribute to these effects. In this study, we used whole-cell patch clamp techniques to record chemically evoked AMPA currents in neonatal mouse motoneurons. Bath application of D₁-like receptor agonist (SKF 39383) increased the AMPA current amplitude and prolonged the decay time constant. In the presence of D₁ receptor antagonist LE300, the effects of DA on AMPA currents were blocked. In contrast, bath-application of the D₂-like receptor agonist quinpirole did not modulate AMPA currents. In the presence of D₂ receptor antagonist L-741626, dopaminergic modulation of AMPA currents was unaffected. These results suggest that augmentation of AMPA transmission by dopamine is accomplished by D₁ receptor-based mechanisms. This short-term modulation does not appear to involve cycling of AMPA receptor into the membrane, since blocking insertion with botulinum toxin C did not affect the augmentation of AMPA currents after activating D₁ receptors. On the other hand, blocking protein kinase A (PKA) with H-89 completely abolished the effects of D₁ agonists. In addition, we used cell-attached single channel recording to demonstrate that stimulating D₁ receptors increased individual AMPA channel open probability and open duration. Our data demonstrate that dopamine increases the efficacy of glutamatergic transmission onto motoneurons by increasing AMPA conductances via a D₁ PKA-based signaling system.